1. Field of the Invention
The present invention relates to heat transfer devices. More particularly, the present inventions relates to tube for a heat exchange, the tube having a turbulator disposed in it which includes an elongated coil length of non-uniform diameter.
2. Disclosure Information
Fin and tube type heat exchangers are commonly used in vehicle, industrial and residential environments for heating and cooling purposes. Typically, these heat exchangers utilize a plurality of hairpin-shaped tubes to form a heat exchanger, such as an air-to-oil cooler or condenser or the like wherein the fluid passes through the plurality of tubes. The number of tubes depends upon the thermal capacity requirements of the fin and tube heat exchanger. Interleaved between the plurality of tubes are a plurality of stacked fin members which aid in dissipating the heat from the condenser as is well known in the art. A manifold interconnects the tubes so that fluid can flow therethrough.
As is well known in the art of heat exchangers, the greatest heat exchange is achieved by providing a turbulent flow around a maximum possible area of material across which the desired heat exchange may take place. Various devices have been proposed to increase material areas, such as, for example, fins, baffles, or corrugations across which passes a cooling medium. Such a device is taught in U.S. Pat. No. 5,381,600, assigned to the assignee of the present invention. The '600 patent teaches the use of corrugated tube walls to increase surface area to increase heat transfer. Other devices have also been proposed to induce turbulence within a heat exchanger. Kao, in U.S. Pat. No. 4,258,782, teaches inserting a cylinder with edgewise fins into a heat exchanger. Megerlin, in U.S. Pat. No. 4,090,559, teaches the use of a spiral brush to turbulate fluid flow. However, all of the prior art approaches have shortcomings relating to either the manufacturing or performance thereof. It would be advantageous to provide a turbulator which is easily inserted into a tube and which is inexpensive to manufacture.